Among dialysis patients, Hispanics have the best survival, followed by blacks, while whites have the worst outcomes, researchers found.

Action Points

Note that this analysis of a population database revealed better survival rates among Hispanics than blacks and non-Hispanic whites.

Be aware that without patient-level data, the factors mediating the relationships between race, ethnicity, and mortality on dialysis remain unclear.

Among dialysis patients, Hispanics have the best survival, followed by blacks, while whites have the worst outcomes, researchers found.

In an analysis of data from a large registry, whites had a substantially higher mortality than blacks or Hispanics over nearly 2 years (30.4 versus 17.9 and 17.5 deaths per 100 years, respectively), Guofen Yan, PhD, of the University of Virginia in Charlottesville, and colleagues reported online in the Clinical Journal of the American Society of Nephrology.

"Examining dialysis survival among racial and ethnic subgroups may help identify care disparities and outcome differences in chronic kidney disease," Yan said in a statement.

Studies have shown a "survival paradox" for black patients on dialysis. Even though blacks in the general population have worse survival than whites, they tend to have better outcomes and survival on dialysis.

But it's been suggested that these results could be confounded by factors such as age, race, or ethnicity; so to better assess dialysis outcomes and survival by race and ethnicity, Yan and colleagues looked at data from the United States Renal Data System gathered between 1995 and 2009 on 1,282,201 dialysis patients.

The median duration of follow-up was 22.3 months.

The researchers performed analyses looking at whites and blacks with and without including Hispanics in each group. They found that non-Hispanic whites had a substantially higher mortality rate than non-Hispanic blacks or Hispanics. Thus, when Hispanics were excluded from the white race category, mortality rates among whites increased -- and blacks still had a significantly lower mortality than whites in almost all age groups (HR 0.70 to 0.87, P<0.001 for all).

The only exception was the youngest group of patients: among those ages 18 to 30, mortality rates were worse for blacks than for whites (HR 1.19, 95% CI 1.13 to 1.25).

The reasons for the findings aren't clear, Yan and colleagues wrote. Hispanics have no particular advantage in access to clinical care, and they have the lowest rates of health insurance in the U.S., the investigators reported.

However, it may be that black and Hispanic patients with kidney disease are more likely to die before they develop kidney failure, Yan and colleagues wrote, so those who survive are generally healthier and more likely to live longer with kidney failure.

The findings are limited by the potential for misreporting of covariate data, including race and ethnicity, and because patient details weren't available in this large administrative database.

Still, the researchers concluded that since the mortality risk among dialysis patients is lowest in Hispanics, intermediate in blacks, and highest in whites, it is important in future research to distinguish Hispanic whites from non-Hispanic whites.

"Continued effort to discern the factors responsible for the general survival advantage of black and Hispanic patients may yield major clinical and public health implications for the U.S. [end-stage renal disease] and potentially, [chronic kidney disease] populations," they wrote.

The study was supported by the National Institute of Diabetes and Digestive and Kidney Diseases.

The researchers reported no conflicts of interest.

Reviewed by F. Perry Wilson, MD, MSCE Instructor of Medicine, Perelman School of Medicine at the University of Pennsylvania and Dorothy Caputo, MA, BSN, RN, Nurse Planner

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